Is milkweed an invasive weed?

Although “weed” is part of their name, milkweeds are native and beneficial wildflowers. There are over 73 species of milkweed native to the United States, and about 30 species are used regularly by monarchs.

In the U.S., neither the federal government nor any states list milkweeds as noxious weeds. In fact, at least five species are listed as state or federal endangered species (Borders and LeeMäder 2014).

According to the North American Invasive Species Network, an invasive species is “a non-native species...whose introduction causes or is likely to cause economic harm, environmental harm, or harm to human health.” The invasiveness of any plant depends on the characteristics of the species and where it is planted. Some species of milkweed, like common milkweed (Asclepias syriaca), have a tendency to be more aggressive in garden settings or disturbed areas, and thus have a reputation of being “weedy”.

If you are interested in growing milkweed, plant species that are native to your region. If you are concerned about milkweed spreading too much, avoid species that are particularly good at clonal reproduction or are prolific seed producers. Click here for more information on selecting native milkweed species and planting milkweed for monarchs.